What is Hyperstimulation?

What is Hyperstimulation | Australian Concept

The purpose of infertility treatment including IVF and other assisted reproductive techniques is to increase the chances of infertility for infertile couples. This treatment is intended to stimulate the ovaries to ensure that several ovarian follicles are developed instead of just one that develops in a normal natural cycle. This helps the doctors to collect several oocytes (eggs) and eventually several embryos to be transferred into a female uterus.


Ovarian Hyper stimulation syndrome commonly called as OHSS is a rare iatrogenic syndrome, which occurs as a result of these ovarian stimulation treatments and fertility drugs for ovulation. The most commonly used fertility drugs are the gonadotropin drugs, clomid and letrozole.

Gonadotropins includes FSH and LH and are used in injectable form whereas clomid and letrozole are taken orally. The purpose of both is to stimulate the ovaries in order to obtain increased number of oocytes at the time of egg retrieval.

WHO clinical classification:

The classification of Ovarian Hyper Stimulation Syndrome is based on the signs and symptoms experienced by the female patients, and are divided into mild, moderate and severe forms, based on the degree of their severity these are classified as the following;

Mild OHSS:

Increase in Ovarian volume, less than 5cm

Excessive steroid production

Pelvic discomfort

Moderate OHSS:

Increase in Ovarian volume, between 5cm to 12cm

Abdominal Distension

Digestive problems like nausea, vomiting and diarrhea

Severe OHSS:

Increase in Ovarian volume, greater than 12cm

Renal failure

Ascites (accumulation of excess fluid in the abdomen or peritoneal cavity)

Pleural effusion (accumulation of excess fluid in the pleural cavity, between the layers of the lungs and the rib cage)

Coagulation disorders (blood disorders leading to disruption of clot formation and hence bleeding)

This classification helps to determine the type of treatment required, should the patient experience ovarian hyperstimlutaion signs and symptoms. Normally the infertility specialists are familiar with these signs and symptoms, and hence are able to detect them in order to provide appropriate treatment required. Since these are serious complications and can be potentially life threatening if left untreated, they should be catered to very effectively.

If you experience any of the above mentioned signs and symptoms during an ovarian stimulation cycle, you should consult your doctor immediately and pay him or her a visit.

Risk Factors:

The risk of having hyperstimulation can be prevented by screening the patients for risk factors, this should be considered before starting the treatment.

The Risk Factors of having the complication of Ovarian Hyper stimulation syndrome are as follows;

Your age is 30 years or younger

You have Polycystic ovarian syndrome

Your AMH (Anti Mullerian Hormone) levels are high

You are underweight

You have a history of developing OHSS in the past

This means a younger patient with a normal ovarian reserve and with polycystic ovarian syndrome is at a higher risk of developing hyperstimulation complications than an older patient with a decreased ovarian reserve. To check for ovarian reserve, the most commonly used test by our doctors is the level of Anti Mullerian Hormone (AMH).

Prevention of OHSS

When starting the infertility treatment, your specialist doctor must take in consideration, your age, your ovarian reserve, your hormonal levels and the possibility of having polycystic ovarian syndrome, in order to avoid ovarian hyperstimulation.

Also after starting the treatment, your doctor would follow the stimulation response to fertility drugs, using blood tests and ultrasound, and so the gonadotropin doses must be tailored according to individual patient’s response. Thus, if your doctor notices an excessive response to ovarian stimulation, he or she should decrease the dose accordingly.

Although hyperstimulation occurs only after ovulation has taken place, your doctor can still look for signs that suggest increased risk during a particular cycle. If that’s the case, then in response to the fertility drugs, your ovaries will develop an increased number of follicles than expected, and the estradiol or estrogen level in your body would also be higher than normal, meaning that your chances of having OHSS in this cycle are high.

Ideally under such circumstances the doctor would cancel your treatment because pregnancy can worsen OHSS. Your doctor would cancel the insemination process and would advise you to avoid having intercourse if you were undergoing an IUI (intra uterine insemination). Whereas if you were undergoing an IVF treatment then any fertilized embryos would be frozen and saved to be transferred into your uterus at a later date, when your body allows.

An alternative to this cancellation of ovarian stimulation treatment is delaying ovulation and the process is called ‘coasting’. This is achieved by prescribing a Gonadotropin releasing hormone antagonist commonly called GnRH antagonist, that would prevent the LH surge, which is required for ovulation. This delay lowers the risk and severity of complications and increases the chances of carrying on with a successful pregnancy.

One should not exert themselves thinking of these complications, instead you should be in contact with your doctor during the entire process and inform him or her about any alarming signs. Of course your doctor would provide you with the relevant information and material, we have come across some pamphlets delivered by an infertility clinic called Australian concept infertility center, it had a lot of relevant information on hyperstimulation.

Leave a Reply

Your email address will not be published. Required fields are marked *

Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors